Braking mechanism



A. H. CHANDESON.

BRAKING MECHANISM.

APPL'ICATION FILED JULY 8.1920.

Patented Nov. 7, 1922.

Patented Nov. 7, i922.

ALFRED HENRI criannnson, or mean sr PIERRE, B GIUM; sorn trainer SAID ALFRED tanner errannnson, Assrenoa T0 course-nan meannerrenarn on nannies-n (SYSTEI'JIE Lu'rnns) soorn'rn ANOIYIVL'E, or BRU BELGIUIII.

BRAKING MECHANISM.

Application filed July 8, 1920. Serial No. 394,719.

enau'rnn UHDER 'rnn raevrsrous or THE ACT or MARCH 3, 1921, 41 smil n, 1313.

To 64% whom it may concern:

Be it known that I, .PLLrnnn lilunni' GHAN- nnsoN, a subject of the Kin g of the Belgians, residing at Jette Sty Pierre, Belgiiun, have invented new and useful Improvements in li *aking Mechanism (for which I l'iave '[iled applications in Belgium No. 262,108, filed Nov. 27, 1918, and Germany tiled Nov. 29,

1913, No. 24,148), of which the following is a specification.

This invention relates to braking mechanisms of the type in which brake shoes are adapted to act laterally on a braking member or drum secured to the axle or shaft on which the braking action is to be exerted.

in mechanisms of this kind it is essential that the brake shoes shall be uniformly applied against both sides of the braking member and, furthermore, in order to obtain a quick braking action the shoes should he as near the braking member as possible when in their inoperative positions. The .inechanisin, moreover, should be reliable and steady in operation, and it should comprise a small number oi? parts in order to avoid unnecessary complication and weight.

The object of this invention to proride a braking mechanism that wi l answer these rcrpiirements, while being ot a simple, strong and compact structure.

in accordance with the invention the braking member or drum is adapted to he acted upon by two pairs of brake shoes, one on each side of the axle or shaft, and these are o erativel v connected with rods 01 unequal long pivoted to the ends of a (01npcnsating lever which, in turn, is pivoted to an operating lever or member at a point intermediate the ends of said lever hut closer to the end. connected with the shorter rod.

This arrangement offers the advantage, among others, that it is capable of automatic adjustment so that it will also operate normally with brake shoes oi different thicknesses or with shoes in different cmulitions of wear.

T he invention will now he more par- Fig. 2 is a side elevation of the same.

.111 the example shown, the braking member or drum a. is adapted to be eiigaged by two pairs of brake shoes 7r. carried bv pivoted arms (Z depending from the frame 0 oi a ra-ilway coach. There is irovided one pair of arms (Z on each side of the axle Z), and the arms of each pair are connected by means of apair of oppositely threaded. screws 6, f engaged by a sleeve nut g, so that the shoes /i will he moved towards or away from each other by rotating said nuts in one or the other direction.

The brake shoes are held in a vertical posi tion by means of suitable springs r.

The screws (2, j and nuts g are shown to be so j'oustructed and arranged that brat:- lng takes place when the twh nuts are rotated in the same direction. The nuts q are respectively connected to rods 2' and connected together by a lever is to which is pivoted a rod or bar Z adapted to be onerated by fluid pressure or the like. The pivotal connection between the rod Z and the lever 7. intermediate the ends of said lever and, as shown, the distance between said pivotal connection and the head of the rod v1 for actuating the nut g which is coml iaratively near, is less than the distance between said pivotal connection and the head of the rod for actuating the nut g which is farther away. The position of said pivotal connection on the lever 7c is preferably such that the forces exerted by the rods c'. and j on their respective nuts shall be eqiiial. Conseiiuently the arms (Z of both pairs will he acted upon by the screws (2 and j with equal force and the brake shoes 71, applied against the drum a with equal pressure. The equal moments of the rods 2' and j with respect to the axes of the screws 6 and remain substantially uniform whatever he the condition at wear of the brake shoes 72.. Thus, ii the shoes of one pair should wear out quicker than the others, on account of the metal being softer or for any other reason, the lever 71: will. automatically swing about its connection with the rod Z so that the pressure exerted by the two pairs of brake shoes will remain unaltered,

T he two nuts 5/ are connected with one another by a pair of braces m and the nut remote from the operating rod Z is connected to a bracket a rigid with the frame of the car by means of a pair of rods 0 for taking up the pull exerted by the operating rod In operation, the power applied in any desired manner to the rod Z is transmitted by the lever is to the rods 2', j, which rotate the nuts 9 so as to move the screws 0, towards each other and apply the brake shoes it against the sides or the drum a, the lever is automatically taking up such a position that the two pairs of brake shoes are applied with equal pressure to the drum a. W hen power ceases to be applied to the rod Z, this rod and the other parts of the mechanism return to their inoperative positions.

I claim:

1. in a braking mechanism, the combination with a braking drum, oi two pairs of brake shoes mounted for lateral movement on each side of: the axis of said drum, a member for moving the shoes of each pair towards and away from said drum, a rod connected to each of said members, said rods being of unequal lengths, a lever pivotally connected to both rods, and an operating member pivotally connected to said lever at a point intermediate the connections of said lever with said rods,

2. In a braking mechanism, the combi nation with a braking drum, of two pairs of brake shoes adapted to engage said drum on both sides of its axis, a rod operatively connected with each pair of brake shoes, said rods being of unequal lengths, a lever pivotally connected to both rods, and an opcrating member pivotally connected to said lever at a point nearer the connection of said lever with the shorter rod.

3. In a braking mechanism, the combination with a frame, of a braking drum, two pairs oi: hinged arms depending from 1 ,aea

said frame, brake shoes on said arms adapted to engage said drum on both'sides of its axis, oppositely threaded screws connected with the arms of each pair, a nut engaging each pair of screws, a rod operatively connected With each nut, said rods being of unequal lengths, a lever pivotally connected to both rods, and an operating member pivotally connected to said lever at an intermediate point thereof, the lever arm adjacent the shorter rod being shorter than that adjacent the longer rod.

i. in a braking mechanism, the combination, with a braking drum, 1" two pairs of bralre shoes, one on each side of the axis of said bra-king member, a pair of oppositely threaded screws and a nut therei'or connecting the brake shoes of each pair, a crank on each of said nuts, an operating member, and means adapted to transmit a predetermined part of the pull of said incur her to each oi said cranks.

5. in a braking mechanism, the combination, with a braking drum, of two pairs oi? brake shoes adapted to engage both sides of said drum on both sides oi? the axis thereof, and means for moving said shoes toward and. away from said drum comprising a pair ofoppositely threaded screws connected to each pair of shoes, anut enging the screws of each pair, a crank on each of said nuts, a floating lever, and operating inemh aconnected to an intermediate point on said iever, and rods respectively connecting said cranks with the ends of said lever.

in testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

ALFRED HENRI GHANDESON.

Witnesses HENRY W. PLUnnnR, F. Y. ZSERNEY. 

